Nitrate Reduction by an Isolated Strain of Fe(II)-Dependent Autotrophic Denitrification Bacteria

A strain of Fe(II)-dependent autotrophic denitrification bacteria, named W1, was isolated from the sediment of the East Lake in Wuhan and was identified as Pseudomonas sp.. The denitrification performance of W1 under different conditions was investigated in this study. The results indicated that the optimal condition for W1 to remove nitrate was: NO3--N 50 mg·L-1, Fe2+ 500 mg·L-1, and pH 6.8-7.0. After one week’s cultivation under optimal condition, denitrification efficiency of W1 could reach 87.54%. During the process of cultivation, the nitrite concentration was always no more than 0.33 mg·L-1 and there was no ammonia production. It seems that the nitrate was almost converted into N2.